<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        .top {
            width: 100%;
            height: 80px;
            background: #ccc;
            margin: auto;
            text-align: center;
            line-height: 80px;
            border: 2px dashed rgb(107, 107, 107);
        }

        .banner {
            width: 100%;
            height: 60px;
            background: #ccc;
            margin: 5px auto;
            text-align: center;
            line-height: 60px;
            border: 2px dashed rgb(107, 107, 107);

        }

        .main {
            width: 100%;
            /*height: 500px;*/
            margin: auto;
            /*line-height: 500px;*/
        }

        .main-left {
            height: 500px;
            background: #ccc;
            width: 210px;
            float: left;
            border: 2px dashed rgb(107, 107, 107);
        }

        .main-right {
            height: 500px;
            background: #ccc;
            width: auto;
            margin-left: 220px;
            border: 2px dashed rgb(107, 107, 107);
        }

        .footer {
            width: 100%;
            height: 120px;
            background: #ccc;
            margin: auto;
            text-align: center;
            line-height: 120px;
            margin-top: 5px;
            border: 2px dashed rgb(107, 107, 107);
        }
    </style>
</head>

<body>
    <div class="top">top</div>
    <div class="banner">banner</div>
    <div class="main clearfix">
        <div class="main-left">left</div>
        <div class="main-right">right</div>
    </div>
    <div class="footer">footer</div>
</body>

</html>